Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Brandt 6~
A SEALING ARRANGEMENT 2 9 ~ 7 41~
Backaround of the Invention
The invention concerns a sealing arrangement for a pump unit
submersed in li~uid including a water~tight enclosed motor
and a pump with an outlet provided with a flange.
Pump units, which are meant to operate entirely or partly ~ ~ -
submersed in liyuid, are difficult to overhaul iE the unit -
is fixed to the outlet pipe. In ordsr to solve this problem
it is known practice to arrange the pump unit to be lowered
along guides so directed that the pump unit, when placed in
its lower position, has its outlet in contact with a fixed
outlet pipe for the pumped liquid. The pump outlet must : ~:
then be sealingly attached to the outlet pipe without being
fixed with screws or the like.
These known devices thus allow the pump unit to be easily
taken up from the liquid for overhaul, but certain problems
may arise concerning the sealing between the pump unit and
the outlet pipe. ~uring operation of the pump, a force is ;~
established which tries to part the two connection devices.
This problem has up to now been solved by designing the
connection in such a way that gravity acting on the pump
unit has overcome the mentioned reaction force, An example
of such a solution is shown in the Swedish Patent No. 163
212. ;,
Another way to solve the problem is to arrange an elastic
bellows in t-he pump outlet, th~ free end of which is brought
into contact with the flange of the outlet at pump start.
Such a device is shown in the Swedish Patent No 366 104. A
~1sadvantage with this device is that the front end of the
bellows goes beyond the end of the pump outlet flange and
thus can be damaged between the two flanges when the pump
unit is mounted, as said flanges move in parallel at ~hQ ~ 6
phase of the mounting. For this reason it is neither
sultable to arrange an elastic seal ring between the two
flanges as such a ring is easlly moved or perhaps damaged
during mounting of the pump uni t .
According to the invention the arrangement is a simple and
effective way to solve the problem o~ sealing two flanges,
and the sealing will not be damaged if the two flanges
should rub against each other and it is easily replaceable.
Summary of the Invention
The objects and features o~ ths invention are accomplished
by an arrangement for obtaining a sealing between two
opposite flanges which form the connection between a
submersible, easily disconnectable pump unit and a rigidly
attached outlet pipe, which sealing device is brought to its
sealing pocition at pump start. The front end of one of the
flanges is provided with a circular groove around its
oponing, the groova containing a seal ring of elastic
material, which in its rest position is entirely contained
within said groove, and the ring has two lips which form an
angle between each other, one of said lips being pressed by
the pump pressure into contact with the cylindric surface o~
the groove and into contact with the opposing flange for
obtaining a sealing between the two flanges.
~rief DescriPtion of the Drawinqs
The invention i5 dsscribed morP clearly below with re~erence
to the enclosed drawings in which: 2~7~16
Fig 1 shows a pair of flanges without any elastic seal ring;
Fig 2 shows the same pair of ~langes with the seal device
mounted and in rest position; and
Fig 3 shows the device in operating pOsitioll.
Detailed Description of Preferred Embodlment
. ~ '~.' .
Referring to the drawings there is shown flanges 1, 2 and a
groove 3 in flange 1. An elastic seal ring 4 has inner and
outer lips 4a and 4b res,p. A ring formed spring 5, a
pressure pipe 6, and the side walls 7, ~ of the groove 3 are
shown. A not~h 9 is provided in the lip 4b which has
surfaces 10,11 on the latter. ~;
As is shown in Fig 1 a groove 3 is cut in the flange 1 on a
surface heading the surface of the other flange 2. In the
groove there is a seal ring 4, Fig 2, o an elastic material
and which is kept in the groove by gluing or by a slotted
ring-formed spring 5, which expands the seal ring towards -
the cylindric surface of the groove. In order to make it
easler to keep the seal ring in its place during mounting,
the cylindric surface has an angle so that the groove has
less diameter at the entrance. The angle may vary from a
few degrees up to abou~ 30 degrees. The steeper the angle `~
the greater the manufacturing difficulties.
The seal ring 4 comprises two lips 4a and 4b which contact
the bottom of the groove and its ~ylindric surface resp. In
its re~t position, Fig 2, one of the llps 4a contacts the
bottom of the groo~e, while the other lip 4b is directed
~wards and forwards in such a way that it is entirely kept
within the groove 3, not sticking out beyond the end surface
of the flange 1. In this way the lip will not be damaged bv
the other flange 2 during mounting.
When the pump unlt starts to operata, a high pressure is
immediately created in the pipe 6. This pressure presses
the lip 4b outwards in the direction of the cylindric part
of the groove, the end of the lip being pressed against the
other flange 2 thus obtaining a sealing between the two
flanges 1 and 2.
In order to secure that the lip 4a is pressed outwards
during the pressure increase, the surface 10 heading inwards
is wider ~han the opposing surface 11. This means that the ,
lip moves outwardsl even if the pressure initially is the
same on both sides of the lip. In order to further
facilitate the contact with the cylindric surface, there is
a notch 9 in the outer surface 11.
The pressure which presses the lip 4b against the cylindric
surface and the opposing flange 2 increases with the pump
pressure, which means that a good sealing is always
obtained. When the pump stops, the pressure decreases and
the lip 4b returns to its initial, protected position within
the groove 3.
In order to diminish the risk for erosion, thP seal ring is
so designed that it is smoothly adapted to the flanges
without any pockets which may disturb the liquid flow. The
seal ring is preferably extruded and has a profile with only
a slight diameter dif~erence which decreases the risk from a
changing of its form when glued.
Wh.ile the present invention has been disclosed in connec on~
'th a preferred embodiment thereof, it should be unders ood
that there may be other embodiments which fall within the
scope of the invention as defined by the following claims.
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